Im New to the game and wonder which to agents i should unlock now. I heard omen killjoy and raze are good at tze moment. Can i get some advices?

I've been playing ranked with my friend for almost a week now and just today I got this. Anyone know why it just suddenly wouldn't let me play ranked ​ https://preview.redd.it/s0uktdnibdc61.png?width=1300&format=png&auto=webp&s=9b0...